Energy-Efficient LED Signage Retrofits: What Buyers Should Measure

Measure real power at the sign’s AC input before and after the retrofit, and verify that the finished sign meets the same visibility and uniformity requirements. Use the measured power and actual operating hours for each mode to estimate annual energy use.

Set the baseline at the whole sign

Have a qualified technician measure real power in watts at a point that captures all equipment serving the sign, including power supplies and any controllers that remain energized. Use the same measurement boundary before and after the retrofit. A module’s rated DC wattage can help size a system under the selected model’s datasheet conditions, while the AC reading captures what the installed system draws, including conversion losses and controls.

Record the existing schedule, dimming settings and any failed lamps or dark sections when you take the baseline. A partially lit sign can draw less power than it would in its intended operating condition. If the retrofit also changes the schedule, compare both systems on a common schedule to isolate the equipment savings, then use the planned schedule to forecast total energy use.

Translate watts into annual kilowatt-hours

For each steady operating mode, multiply measured input watts by annual hours in that mode and divide by 1,000. Add the results for full brightness, dimmed operation and any standby period with measurable draw. For an animated sign, use the average input power over a representative playlist or log energy over a typical operating period. Compare the annual totals, and keep the highest measured load as a separate input to the electrical review.

Measure light on the finished sign

Agree on the viewing positions and acceptable face brightness, uniformity and color before selecting a layout. If the project uses a luminance meter, mark repeatable points and record the viewing angle and ambient conditions. Include likely trouble spots such as narrow strokes, corners and large uninterrupted areas. Compare readings and visual appearance under similar conditions once each sign has stabilized. For halo-lit letters, assess the illuminated wall as well, since the wall finish and letter spacing can change the appearance.

Use a representative letter or cabinet to compare layouts before ordering for an entire rollout. Match the actual face material, depth and internal finish as closely as possible. HansonLed’s channel-letter catalog lists mini modules with lenses. Check the selected model’s datasheet and use the mock-up to judge spacing in the narrowest strokes. Channel Letter LED Modules

HansonLed’s edge-lit catalog lists a module for boxes. For a cabinet that uses edge lighting, check whether the selected module suits the optical assembly and inspect both the area near the lit edge and the area farthest from it. A face that looks bright near the source can still have a dim center or far edge. Edge Lit LED Module

Specify how RGB effects should work

With whole-module RGB control, the emitters within a module share the same color command. Multiple modules on a common control zone can change together. Individually addressable RGB pixel control lets the controller assign different colors and brightness levels to separate pixels, so one part of a sign can change while another holds its color. Depending on the model, a pixel may contain several emitters. Confirm what one address controls and which controller and protocol the datasheet specifies. HansonLed’s pixel module catalog lists an Addressable RGB Pixel. Pixel LED Module

For a color-changing retrofit, measure the scenes the operator will actually use, including the normal brand color and typical animations. Check the highest-load scene permitted by the selected system for electrical sizing. A brief high-load effect and a steady overnight scene answer different procurement questions, so record both the load and the time spent in each mode.

Buyer’s retrofit acceptance checklist

• Record the baseline AC input watts, operating schedule, control settings and condition of the existing sign.

• Agree on viewing positions and acceptance criteria for brightness, uniformity and color before comparing proposals.

• Document the proposed module model, quantity, layout, power supply and controller on the pilot build.

• Have the installer verify voltage at representative points under load and check supply loading, mounting conditions and environmental suitability against the selected component datasheets.

• Repeat the light and power measurements after installation. Save the results alongside the settings and operating hours used for the annual energy estimate.

Frequently asked questions

Can I compare retrofit bids by adding up module wattages?

Use rated module watts to screen proposed DC loads. For a comparable energy estimate, ask each bidder for whole-sign AC input power at the agreed lighting settings and apply the same operating schedule.

Can a dimmer setting stand in for a power reading?

Measure input power at each setting you plan to use. A controller percentage is a command, and its relationship to AC input depends on the modules, supply and control system.

What if the old sign has already failed?

Look for historical measurements from the same sign or a working counterpart with a comparable configuration. Label any reconstructed baseline as an estimate and record its assumptions. You can still verify the new sign’s energy use and appearance directly.